This invention relates to motor vehicles having safely body structure arrangements by which collision impact forces are transmitted through vehicle door pillars and doors.
In motor vehicles with safety body structures such as have been in use for several decades, efforts are made to keep the passenger compartment largely free of deformation even in severe accidents. In order to achieve this objective when the vehicle is involved in a frontal or offset collision, the front section of such conventional motor vehicles is arranged so that it deforms during an impact while converting kinetic energy to deformation work, and some of the impact forces are transmitted rearwardly to more remote regions of the vehicle by longitudinal members and reinforced side walls of the passenger compartment. In the more remote rear regions the transmitted impact forces are absorbed over large areas and through plastic deformation of the body material.
However, this result is only ensured to an adequate degree if the side doors of the vehicle remain in a closed position during the collision, since otherwise only a portion of the impact forces acting on a front door pillar will be transmitted through the structure above and below the door rearwardly to a door pillar located behind it for absorption in the rear regions of the vehicle. Possible weak points of the doors in this respect include the region of the door lock and the region of the door hinges, which usually deform at their point of attachment or tear out of the door pillar because of inertia when the doors are pushed forward in a frontal or offset collision and because the door pillar may deform rearwardly as a result of the impact forces.
In conventional door hinge arrangements as shown by way of example in FIGS. 6a and 6b, deformation of the door pillar or tearing out of a hinge retaining part welded to the door pillar results first in interruption of the transmission of force through the door hinge itself, and then results in the front part of the door attached to the door hinge being pushed outwardly because the weld seam located between the hinge retaining part and the door pillar tears, starting at its rearward end, and the hinge retaining part is bent outward in the process. This causes the front end of the door to swing out of the door opening toward the side and away from the longitudinal center line of the vehicle so that it can no longer bear against the adjacent door pillar even above and below the door hinges or in the area ahead of the window in the door. This means, in turn, that the chain of force-transmitting components such as door pillars and door beams is broken, causing more severe deformation of the passenger compartment to occur in the front section of the vehicle in an undesirable manner.
In the arrangement described in British Patent Application No. 2,144,797, this disadvantage is avoided by providing a hinge component that is rigidly attached to the door pillar and has two parts which are connected by an additional pin extending parallel to the conventional hinge pin and which, in normal vehicle operation, is rigidly connected by a shear pin to both parts of this hinge component. The shear pin provides an intended deformation point that is destroyed when the vehicle is involved in a collision so as to release the two parts of the hinge component attached to the pillar, permitting them to swivel relative to each other. This swivel movement causes a displacement of the hinge pin, and thus of the rear end of the door that is rigidly connected to it, toward the vehicle's longitudinal center line. In this way, the arrangement assures that the above-described chain of force transmitting components is preserved in a collision.